It's not Western Washington, but Naches has some nice trails that you can run in a stock Samurai.  You should also be able to do most of Tahuya over on the Peninsula.
Walker Valley is available, but beware of some body damage.  That place has a great way of reaching out and smacking vehicles when your not paying attention.  

Evans Creek is doable, only a few spots that will slow you down.  Reiter Trails will be opening back up in a year or so, then you will have some new trails of all difficulties.
Where are you located at?  I am a member of a club that meets up once a month in Mill Creek, you can check out our page at 
www.crawlersnorthwest.com if your interested.  We aren't a Suzuki only club, it just seems that way.  
